Interface ServicePlan<DateType>

interface ServicePlan<DateType extends Date | string = string> {
    activeFrom: DateType | null;
    dataCategoryMapping: DataCategoryMapping | null;
    dataPoolUsage?: {
        accountNumber: string;
        dataBlocks: DataPoolUsage<DateType>[] | null;
        lastUpdated: DateType;
    };
    isMobilePlan: boolean;
    isoCurrencyCode: string
    | null;
    isOptedIntoOverage: boolean;
    overageDescription: string | null;
    overageLine: OverageLine;
    overageLineDeactivatedDate: DateType | null;
    overageName: string | null;
    productId: string | null;
    subscriptionActiveFrom: DateType | null;
    subscriptionEndDate: DateType | null;
    usageLimitGB: number;
}